Various pieces of apparatus have been devised for washing the hands, or hands and forearms, of persons, such as surgeons and others, who work in clean and sterile environments. Co-pending application for U.S. patent Ser. No. 112,299, filed Oct. 26, 1987, U.S. Pat. No. 4,817,651, by W. E. Crisp et al for "HAND AND FOREARM CLEANSING APPARATUS", which is assigned to the same assignee as the present application, discloses apparatus which is particularly effective for this purpose. That patent application discloses and evaluates other patented apparatus in this same field. The disclosure of the Crisp et al. application is incorporated herein by reference as illustrative background art.
In the apparatus disclosed in the aforementioned Crisp et al. patent application, hand washing is accomplished by circulating a washing liquid through washing chambers into which the user inserts his or her hands. The apparatus has user manipulated controls by which the user determines the type of washing agent to be employed, possibly the sequence of application of various washing agents, and initiates the washing cycle.
One might think that the periodic, repetitive operation of hand washing apparatus of this type would keep the apparatus clean. In other words, you would not have to periodically clean the apparatus itself in a procedure or cycle separate and apart from the usual washing cycles. However, it has been observed that there are certain normal and abnormal operating conditions which make it desirable to clean the apparatus itself to insure its capability of effectively washing hands.
In the normal operation of hand washing apparatus transient bacteria is removed from the user's skin. Not all of this bacteria is flushed from the washing chamber and, with repeated washing operations, a significant quantity of such bacteria may build up in the washing apparatus. If this build up is allowed to continue it is possible for the bacteria level to reach the point where the user's hands can become contaminated rather than cleaned or only partially cleaned during washing. Thus, the performance of the washing apparatus can become impaired.
Such undesirable build up of bacteria could possibly be prevented by incorporating more powerful washing agents in the hand washing cycles. This generally is not feasible because the skin of many users could not tolerate the more powerful agents required to destroy the bacteria.
It is also possible for bacteria to actually grow within the washing apparatus. Thus, over time, particularly if the apparatus is used infrequently, an objectionable build up of bacteria may occur.
Another normal operating condition which can contribute to a build up of bacteria or other contamination of the washing apparatus is the servicing of the apparatus. This usually requires that the interior of the apparatus be invaded by the hands of a service person and those hands may be particularly unclean and capable of imparting infectious agents into the apparatus.
And, lastly, at least one abnormal operation of the apparatus can lead to an undesirable build up of bacteria in the apparatus. Interruption of electrical power to the apparatus is such a condition. Any prolonged power interruption which prevents the apparatus from going through normal wash cycles leaves the apparatus vulnerable to growth and build up of bacteria therein.
There is a need, therefore, for appropriate apparatus and methods for cleaning the washing apparatus periodically to stem the build up of bacteria likely to be caused by any of the aforementioned normal and abnormal operating conditions.